Renewable Energy and Electronics

Monday, October 28, 2013

Human ingenuity may be our best weapon to find more energy for the future. And not too surprisingly, electronics is playing a vital role in this quest.

Already electronic devices like turbines, generators and electric motors put electricity at our fingertips for innumerable uses. Microprocessors electronically control fuel injection systems, allowing internal combustion engines to burn hydrocarbons faster, hotter, in less space, i.e. more efficiently. Programmable thermostats and solid-state LEDs in light bulbs and other appliances are helping to save energy in many buildings – at home, the office or at school.

The race is on to find substitutes for, or at even more efficient usage of, petroleum-based fuels. Well maybe it isn’t a race. Petroleum-derived energy, uranium and coal will probably be around for centuries. But the pursuit for renewable energy sources is getting a great deal of attention and has growth potential. People with a working knowledge of electronics may be able to serve these diverse industries if they are so inclined.

Ethanol, Biodiesel

Ethanol and biodiesel are the two most popular renewable energy liquids. The U.S. is trying hard to produce more of them.

According to the Renewable Fuels Association (RFA) in Washington, DC, American biorefineries made about 3.9 billion gallons of ethanol in 2005. Production could surpass 4.5 billion gallons this year. The National Biodiesel Board in Jefferson City, Missouri reported that about 75 million gallons of biodiesel were manufactured last year. This was up an impressive 300 percent from the 25 million gallons in 2004.

The Energy Policy Act of 2005 set a renewable fuels standard or a national baseline for renewable use of 7.5 billion gallons by 2012. However, the U.S. Energy Information Administration (EIA) reports the nation uses, on average, more than 14 million barrels of transportation fuel everyday, including some 9 million barrels of gasoline, 4 millions barrels of diesel fuel and more than 1 million barrels of kerosene-type jet fuel. With 42 gallons to a barrel, that equates to approximately 600 million gallons a day. We Americans are tremendous energy hogs!

So in six years, if the renewables goal of 7.5 billion gallons is met, ethanol and biodiesel will still be yielding only about 3% of American liquid energy needs. Six years from now! So it will be a long uphill climb to ethanol and biodiesel nirvana.

Still, every little bit of energy helps. And there are many good things about ethanol and biodiesel. It is American made, reduces foreign oil (by about 120 million barrels a year, or a six-day supply for the country), slightly lowers greenhouse gas emissions (the RFA estimates by 7.8 tons a year, the equivalent of taking 1.2 million cars off American roads), and assists the agriculture industry.

Today, ethanol is being used in many places around the world. In the U.S., it is blended in more than 40 percent of the nation’s gasoline. In some regions of the nation, it has replaced the gasoline additive MTBE (methyl tertiary-butyl ether) because of water contamination concerns and other factors. In the summer, there were 101 ethanol biorefineries operating in the U.S. Most of these are located in the Midwest and in the big corn producing states like Illinois, Iowa, Minnesota, Nebraska and South Dakota.

Meanwhile, motor vehicle manufacturers such as Ford, General Motors and Daimler-Chrysler, are ramping up production of ethanol automobiles and trucks. There are an estimated 5 million flex-fuel vehicles on the road today, able to operate on gasoline or on a blend of E85 (85% ethanol) and 15 percent gasoline. In the next four years these three firms are expected to double their flex-fuel vehicle production, up from about 1 million this year to 2 million flexfuel vehicles in 2010.

In a recent GM company news release, Ed Koerner, vice president of GM North America Engineering, discussed how the company is able to engineer many of its fuel-efficient, flex-fuel vehicles.

“Getting the basics right in the development of our vehicles is critical,” Koerner explained. “We continue to use our significant technical competency, key fuel efficiency tools, and world-class laboratories to further improve vehicle fuel economy. We know that we must deliver outstanding fuel economy as well as all of the other vehicle attributes that our customers demand.”

GM engineers use a computer-based fuel economy model to determine how energy is used and lost in its vehicles, particularly with powertrain efficiency, chassis system and electrical system losses, mass and aerodynamics. Engine friction, aerodynamic drag and the transmission contribute to the greatest energy losses on combined EPA cycle testing, comprising of nearly 60 percent of the mechanical energy.

“Once we determine where the most significant opportunity for improvement exists, we evaluate how to best optimize fuel energy during the early stages of the design process,” Koerner said. “We use our analytical modeling expertise to help us realize the best solution to improve fuel efficiency while at the same time to allow us to get our vehicles to market faster.” Ethanol can be made from many agricultural feedstocks, like corn, sugar cane, sugar beets or other inedible biomass substances like corn stalks or switchgrass. Right now American ethanol is made almost entirely of the American corn.

The U.S. Department of Agriculture (USDA) reported approximately 2.65 gallons of ethanol can be made from one bushel of corn using a wet mill process, or 2.75 gallons per bushel using a dry mill process. Using 2.7 gallons per bushel as an average, about 0.37 bushels is required to make one gallon of ethanol. That means that 2005’s production of 3.9 billion gallons of ethanol used about 1.4 billion bushels of corn. The USDA estimated last year’s American corn crop at about 11.1 billion bushels. So about 13% of the crop went to ethanol production.

That’s one of the criticisms of using corn for ethanol. Should corn be used to feed people and livestock or power motor vehicles? Food or fuel? In a couple of years, ethanol production could be using 20 percent or more of the nation’s corn crop. Proponents say more corn can be planted, but that can affect corn prices too.

There is also the argument that it takes too much energy to produce ethanol. Studies vary on this subject. One U.S. Department of Energy report from 2005 concluded the “ethanol energy balance” is positive, since there is an average 67 percent more energy in a gallon of ethanol than it takes to produce it. Others have explained it as follows: it requires 1 unit of energy, including petroleum or electricity, to produce 1.3 energy units of corn grain ethanol. But it takes energy to produce, process and refine or transport all kinds of energy, including oil and gas, coal, uranium, and so on.

In July, the National Taxpayers Union (NTU) said ethanol producers receive a 51-cent-a-gallon federal tax credit, and both consumers and taxpayers have seen few benefits from growing federal subsidies to the 30-year-old ethanol industry that has yet to become self-sufficient. In addition, the NTU said ethanol is expensive to produce and transport, since it can only be moved by truck or train, and generally not by pipeline (ethanol absorbs water and impurities that normally reside in fuel pipelines, and up to now, insufficient volumes are available to transport by pipeline). And drivers can expect a 5 to 15 percent drop in fuel economy, using E85.

All these facts may be true. But as a nation, we could use ten, twenty or even thirty times more ethanol. We could use 1,000 biorefineries, not just 100!

To meet that quota, we need to be processing other agricultural products, besides corn, into ethanol. That should include so-called “cellulosic ethanol” that is produced from a wide variety of biomass feedstocks including agricultural plant wastes (corn stover, cereal straws, sugarcane bagasse), plant wastes from industrial processes (wood chips, sawdust, paper pulp) and energy crops grown specifically for fuel production, such as switchgrass. Basically, any kind of plant that rots can be turned into energy through fermentation and distillation.

Many truck owners and fleet operators are interested in renewable biodiesel fuel. In the U.S. most biodiesel is made from soybean oil and is often blended with petroleum diesel in ratios of 2 percent (B2), 5 percent (B5), or 20 percent (B20). It can also be used as pure biodiesel (B100). Biodiesel fuels can be used in regular diesel engines, and can also be stored and transported using diesel tanks and equipment.

Many praise biodiesel usage because it is renewable, burns cleaner than regular petroleum diesel, and again, is American made. However, some question the fuel’s long-term ability to run in colder climates (where it might cloud or thicken), and its effect on seals, hoses, etc., especially in older engines that were not specifically designed to run on biodiesel. Wind and Solar

The EIA charts electric power generated from a number of renewable energy sources. In 2005, the top four of these in total power generated were conventional hydroelectric, municipal solid waste and landfill gas, geothermal, and wood or wood waste generated electricity. Wind power came in fifth, with solar in last place (“behind other biomass byproducts”). However, wind power is the fastest growing power source, on a percentage basis.

U.S. wind energy installations now exceed 10,000 megawatts (MW) in generating capacity, and produce enough electricity on a typical day to power the equivalent of over 2.5 million homes, the American Wind Energy Association (AWEA) announced in the summer (a megawatt of wind power generates enough to serve 250 to 300 average homes). This 10,000 MW saves about 600 million cubic feet of natural gas a day, or about 3.5% of the natural gas used nationwide to generate electricity.

“Wind energy is providing new electricity supplies that work for our country’s economy, environment, and energy security,” said AWEA Executive Director Randall Swisher. “With its current performance, wind energy is demonstrating that it could rapidly become an important part of the nation’s power portfolio.”

The industry is gaining momentum as it grows. The first commercial wind farms were constructed in California in the early 1980s, and after reaching 1,000 MW in 1985, it took more than a decade for wind to reach the 2,000-MW mark, in 1999. Since then, however, installed capacity has grown fivefold. Today, the industry is installing more wind power in a single year (3,000 MW expected in 2006) than the amount operating in the entire country in 2000 (2,500 MW).

The AWEA also said wind energy is creating new jobs. During the past year or so wind turbine manufacturing companies have opened facilities in Iowa (Clipper Windpower), Minnesota (Suzlon Energy ) and Pennsylvania (Gamesa Wind U.S., LLC). Two other important companies installing wind turbines in the U.S. are General Electric and Vestas Wind Systems, a Danish company.

Finally, a few words about solar energy. Because of the work of electronics engineers and technicians, the cost of photovoltaic (PV) cells has fallen dramatically since the early 1970s. But they still cannot compete economically with more conventional sources of energy, especially on a large scale.

The EIA estimated more than 134,000 PV cell and module units, plus some 14,000 thermal collectors, were shipped in the U.S. in 2005. About 60% of these total shipments went to two states, California and Florida. Around and above the planet, solar energy is being used for isolated applications - in outer space, at the polar ice caps and in remote places. Others use it because of conscientious concerns and a desire to use a clean, sustainable energy source. Many groups or individuals place PV cells or solar water heaters in their backyards or on their roofs, canopies or elsewhere.

Do all the renewable sources have a role to play in the U.S.? Absolutely. Are there going to be challenges in manufacturing large quantities of energy from them? Yes. But quite possibly, in another generation, they could be yielding as much as 20-25% of the American energy supply. With more government, industry and private investment and research, including some provided by those savvy in electronics, these renewables can become even more important in the future, whether they are collected from the wind, the sun, agricultural products, hydroelectric dams, garbage or underground geothermal sources.